LONG TERM IMMUNOGENICITY OF THE JAPANESE ENCEPHALITIS VACCINE IC51 (JE-PIV). AN UNCONTROLLED PHASE 3 FOLLOW-UP STUDY - IC51-303

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

EU CTR

Registry ID

EUCTR2005-000253-29-DE

Enrollment

3300

Registered

2005-06-27

Start date

2005-08-01

Completion date

Unknown

Last updated

2012-03-19

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Japanese encephalitis. This study is a follow-up to the pivotal immunogenicity and safety studies IC51-301 and IC51-302.

Interventions

Pharmaceutical Form:

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: -Subjects correctly included in and having completed clinical studies IC51-301 or IC51-302 with at least one vaccination. -Written informed consent for study IC51-303. Only for the immunogenicity part: -Subjects correctly included in and having completed study IC51-301 or IC51-302 according to the protocol with the required amount of injections (IC51-301: 3 / IC51-302: 2). Are the trial subjects under 18? no Number of subjects for this age range: F.1.2 Adults (18-64 years) yes F.1.2.1 Number of subjects for this age range F.1.3 Elderly (>=65 years) yes F.1.3.1 Number of subjects for this age range

Exclusion criteria

Exclusion criteria: -Inability or unwillingness to provide informed consent and to abide by the requirements of the study. Only for the immunogenicity part: -Known negative (< 1:10) anti-JEV neutralizing antibody titer (PRNT) 28 days after the last vaccination in the preceding study or thereafter. -Subjects with any condition which in the opinion of the Investigator makes the subject unsuitable for inclusion. -Known randomization to JE-VAX® or placebo

Design outcomes

Primary

Measure	Time frame
Main Objective: To investigate the immunogenicity of IC51 (JE-PIV) in subjects 24 months after the first vaccination.;Secondary Objective: To investigate the immunogenicity of IC51 (JE-PIV) in subjects 6, 12, 36, 48 and 60 months after the first vaccination. To analyze the safety of IC51 (JE-PIV) 6 months after the first immunization. To investigate the frequency of vaccination-related adverse events during the study period. ;Primary end point(s): Immunogenicity: -Percentage of subjects with seroconversion rate (anti-JEV neutralizing antibody titer equal to or greater than 1:10) 24 months after the first vaccination. Safety: -Frequency of possibly or probably vaccination related adverse events. -Rate of serious adverse events and medically attended adverse events up to 6 months after the start of the immunization.	—

Measure

Time frame

Main Objective: To investigate the immunogenicity of IC51 (JE-PIV) in subjects 24 months after the first vaccination.;Secondary Objective: To investigate the immunogenicity of IC51 (JE-PIV) in subjects 6, 12, 36, 48 and 60 months after the first vaccination. To analyze the safety of IC51 (JE-PIV) 6 months after the first immunization. To investigate the frequency of vaccination-related adverse events during the study period. ;Primary end point(s): Immunogenicity: -Percentage of subjects with seroconversion rate (anti-JEV neutralizing antibody titer equal to or greater than 1:10) 24 months after the first vaccination. Safety: -Frequency of possibly or probably vaccination related adverse events. -Rate of serious adverse events and medically attended adverse events up to 6 months after the start of the immunization.

—

Countries

Germany, United Kingdom

Outcome results

None listed

Source: EU CTR (via WHO ICTRP) · Data processed: Feb 4, 2026